1. Field of the Invention
The present invention relates to a reading device for use with dobbys.
2. Prior Art
In a dobby equipped loom, it may happen that the weft thread that has newly been passed through the warp threads breaks as a result of one thing or another. If this occurs, in order to keep the pattern of fabric in a flawless, uniform condition, the broken thread must be removed and replaced with a new weft thread. To do this, the loom is stopped and the dobby is manipulated back to the reading position at which the breakage took place. The cylinder on which the pattern cards or the pegs for the control of the pattern are carried is reversed for one pick and the loom is inched backward until the shed in which the broken thread is engaged is opened enough to release it. This is called "reverse operation". After the broken thread has been removed, the cylinder is rotated back to the normal operating position and the weaving is resumed.
Apart from this operation for a broken weft thread to be removed, separate adjustments may be performed in the shed and the warp threads. This is done by lowering or raising the different groups of heddle frames to align them at the given heights. This operation, called "levelling", in some of the prior art dobby equipped looms in which the peg cylinder is displaceable from operating position, is carried out, with the peg cylinder being moved away out of normal engagement with the associated pegs so that the peg cylinder will not be interferred during the leveling.
However, in those conventional devices in which the peg cylinder is displaceable, reversal tends to result in the peg cylinder being accidentally displaced off center, causing the engaging hooks to improperly engage with the associated pegs. For normal weaving operation, the pegs should impart precise control to the engaging hooks in timed engagement therewith to thereby raise or lower the different groups of heddle frames which in turn allow the warp threads to interweave the weft threads to produce a desired pattern. Therefore, if the engagement of a peg with its associated pair of engaging hooks goes out of order, then the entire operation is seriously impaired.